Variation of soil respiration and its components in hemiboreal Norway spruce stands of different ages

TLDR: In this paper, the effect of trenching on microbial and soil characteristics was investigated in Norway spruce stands of different ages, and the results indicated the importance of soil respiration partitioning during a limited number of years.

Abstract: Understanding the linkage of soil respiration (Rs) with forest development is essential for long-term C cycle models. We estimated the variation and temperature sensitivity (Q10 value) of Rs and its hetero-, (Rh) and autotrophic (Ra) components in relation to abiotic and biotic factors in Norway spruce stands of different ages, and the effect of trenching on microbial and soil characteristics. Trenching method was used to partition Rs into Rh and Ra. Ingrowth core method was used to estimate fine root production. Soil microbial biomass was measured using manometric respirometers. Rs varied in differently aged stands demonstrating non-linear response to development stage. The variation of Rs was explained by changes in biotic factors rather than by changes in soil microclimate. Rh was more sensitive to Ts than Rs or Ra. After 4 years of trenching soil pH, N, SOM and dehydrogenase activity were significantly changed in trenched plots compared to control plots. Different Q10 values of Rh and Ra in stands of different ages indicate the importance of Rs partitioning. Trenching should be used during a limited number of years because of the possible changes in chemical characteristics of soil and in the activity of soil microbial community.